G.Lite: Mass Market ADSL

Once upon a time, 1200 bps was a fast modem and 230 kbps LocalTalk was a decent network speed.

That was a long time ago. Today, most modems are of the 56k variety - although the name is something of a misnomer. These 56k or v.90 modems can download files at up to 53 kbps. In the real world, download speeds of 44-48 kbps are typical.

On the flip side, v.90 modems have limited upload bandwidth, with a 33.6 kbps ceiling. In fact, the faster your download, the slower your upload, and vice versa. Phone lines only have a total bandwidth of about 64 kbps, bandwidth which must be shared by data moving in both directions.

V.90 modems manage their trick of breaking the 33.6 barrier by operating in digital mode for downloads. However, the nature of phone lines restricts them to analog operation when sending data.

ISDN

The next speed step beyond analog modems is ISDN, which uses one or two digital phone lines and offers 56-64 kbps per line. My home network uses ISDN with a total bandwidth of 128 kbps - over twice what a 56k modem can do and nearly four times what a strictly analog modem (33.6 kbps or slower) could offer.

But it comes at a price. I'm paying about $50 per month for the phone lines, then pay my ISP an higher-than-usual rate for the faster service.

I've grown past 56k, but the step up to ISDN was expensive and doesn't provide nearly the bandwidth I'd like.

ADSL

For the past few years, vendors have been working on ADSL (asymmetrical digital subscriber line) technology. Unlike older modems, the various DSL designs send a high speed digital signal over your phone lines. And unlike ISDN, DSL can maintain a full-time internet connection while leaving your phone line available for phone calls and faxes.

The problem has been a lack of standards. Some DSL designs can potentially reach 6-8 Mbps download speeds, providing close to ethernet performance. Others have been less ambitious, trying to keep cost down and offer a broader network. (The faster a DSL connection, the closer you must be to a phone company switching station.)

Enter G.Lite

The personal computer industry is rapidly embracing G.Lite, a cost effective DSL technology with good enough performance for most users most of the time.

If you read PC Magazine, you may have noticed that Compaq includes G.Lite modems with some models, promising up to 1.5 Mbps internet connections. Of course, the fine print says it may not be available yet, but the same modem also works with regular 56k service.

Compaq is very forward-looking. I hope Apple will do the same with the next generation iMac. G.Lite has the potential to displace analog modems and ISDN connections about as quickly as the phone companies and ISPs can implement it.

G.Lite is asymmetrical, promising download speeds as high as 1.5 Mbps and upload bandwidth of 384 kbps. That's over 25x the speed of a 56k modem for downloads, and nearly 12x the speed for uploads. Compared with dual channel 128 kbps ISDN, download bandwidth is up to 12x faster and uploads up to 3x faster.

Best of all, you won't need a digital phone line -- G.Lite works on your regular line, although it requires your phone company to switch that line to allow high speed data transfers.

G.Lite modems will cost about what 56k modems did when they were introduced, somewhere around $200. And, like 56k modems, they're sure to drop in price over time.

Beyond speed, G.Lite and other DSL protocols have two huge advantages over analog modems and ISDN:

1. You have a full-time connection, so you don't have to wait while your computer or network reconnects to the internet. (Well, maybe after a power outage or if you've powered down your modem.)
2. Cost. Although initially expected in the US$50-80 range, G.Lite rates will eventually drop to the US$30 range as the market expands and various companies vie for your business.

If G.Lite were available here today, I'd switch in a heartbeat. Eliminating the $50 a month to Ameritech for two ISDN lines would cover the cost of G.Lite service. At the same time, I'd have a much faster internet connection.

The only question I have is, "When will they offer it in Grand Rapids, Michigan?" 

Further Reading

• New flavor of DSL brings faster, cheaper Net access, CNN, 8/13
• G.Lite FAQ, Universal ADSL Working Group
• Cable or DSL?, 56k Modem Page, 8/11
• Modems' last stand, Macworld
• Mac-friendly DSL providers
• Beyond 56k modems: Cable and DSL, MacFixIt